hi thanks for your input, but I want to know if it can be done using ATs commands and mobile connected by
usb port and my clients have a mobile which are sent to all clients your outstanding balance and
other recall cases medical appointments

this link http://aimerrivera.wordpress.com/2009/11/06/envio-de-sms-a-traves-de-puerto-com-del-pc-mediante-vb-net/
is the way I want to, but I can not connect the phone to the pc and it looks like a modem